Air-compressor.



A. O. GARPENTER.

AIB COMPBESSOB. urmouon !ILED JAN. 19. eoe.

972,161 Pat nta& Oct. 11, 1910.

' 2 SEEETB-BHEET 1.

UNITED sTATns PAT NT OFFICE.

.ALLAH 0. OABPENTEB, OF FBANKLIN, PENNBYLVANIA, ASSIGNOB TO CHICAGO?NEU- KATIC '10014 COMPANY, OF CHICAGO, ILLINOIS, A. COBPORATION OF NEWJERSEY.

AIB-COMPBESSOB.

Speciflcation o! Letters Patent.

Patented Oct. 11, 1910.

Application mea January 19, 1909. Serial xo. &73,174.

To all whom i: may com-cm:

;Be it known that I, ALLAN O. CARPENTER, a citizen of the United States,-esiding at Franklin, in the oounty of Venango and State ofPennsylvania, have invented certain new and useful Improvements in Air-Compressors, of which the following is a specification.

My invention elates to air compressors and the ob'ect thereof is toprovide novel, eflicient an reliable means for relieving an aircompressor of its load by so controlling the passage of air to or fromthe com ression cylinder that the amount of ar cilvered by thecompressor may be dininished or interrupted without stoppng or retardingthe movements of the Operating parte of the oompressor, such diminuto inthe amount of compressed air delivered diminishing the work required ofthe conpressor.

My unloader device may be appled to compressors which have mechanicallyoperated rotary, or semi-rotary valves, and which are provided withvalves to prevent the return of compressed air into the compressionchamber. The unloader dei-'ice or Valve is separate from the regularrotary or semi-rotary air ralve, and is operated by an independent echaswith the result that I avoid complicated driving mechanism such as isnecessary when the regular air Valve itself is used also as an unloadervalve. Moreover, by the Construction of my unloader valve, I avoid thefornation of a se arate or additional assa or chanber w ich would add tothe un esirable clearance space of the compression chamher, and makepossible a simple Construction and ready means of application for itsoperating nechanism.

Other novel and advantageous features of Construction and operation willbe appareni from the description hereinafter given.

In the drawings F igure 1 is a lmgitdinal section thron -h thecompression cylinder and cylinder heads of a compressor in which myinvention is embodied; F ig. 2 a end View of one of the cylindeheads onthe cylider side showing a portion tle'cof broken away to expose a en(of one of the air valves and my unloader vulve; Fig. 3 a section on theirregular line 3-3 of Fig. 2; Fi 4 a side elevation of the com 'cssioncy inder and the mechanism applie thereto for Operating my unloadervalves; Fig. 5 a section through the regulating and Operating cylindersof the mechanism for Operating the unloader va lves; and Figs. 6 and 7erspectives of one of the unloader vali-'es and one of the air valvesrespectively.

The construct-ion herein illustrated and now about to be describedrepresent-s one 'of the embodiments of my invention althou h as will beunderstood my invention may e embodied in other forms or strnctures without departing from the spirit thereof.

The compressor elements illustrated in Fig. 1 are of the usual andwell-known character comp'ising the compression cylinder A within whichthe piston B is reciprocally operated and which is closed at its ends bythe cylinder heads C C. within these heads are located the air inletvalves D D e which are hcrein shown as of the semi-rotary type andoperate in the valve chambers E E to govern the communication betweenthe inlet chanher b and the compression cylin- (ler through the ports d.It. will be understood thatwhenever in this spccifixation, or in theclains, I refer to a rotary inletvalve or unloader valvc, I use the termin a generic sense as applied to both the so-called rota'y andsemi-rotary types. In the cylin- (ler heads are also arranged thedischarge valves F F which in the present instance are of the puppettypeand arranged to permit of the discharge of air compressed by the pistonfrom the compression cylinder into the discharge chambcr and passage G.The inlet valves D are operated by an Y desired eans such as the 'ockerarms 2 operatively connected therewitl in the wellknown mauner; andmoreover such valves are similar to the inlet valves in ordinary usewith the exception that they are short` ened axially so as to allowspace within the valve chambers for my unloader valves H, each of whichis a'rangcd end-on and in axial alinement with its inlet valveasillustrated in F ig. 2.

It will be understood that I cmploy two unloader valves one for eachinlet. valve and us such unloader valves are similar in construction andmode of operation n description of one of tlen will suflice for hotla. ypreference the meeting ends of un nlet valve and its unloader valve arelocated d rectly over a cross-piece a in the oommuncuton hetween theinlet chamber I and the valve chamber E, Fig. 2. The arrangement is suchthat the inlet vali-'e D with its usual cut-away portion d' is adaptedto control the port (l practically for the greater port-lon of ts lengthwhile the unloader vah-'e H s adapted to overn the remander thereof butnormally c oses such remaining portion. For the purpose of so governngits end of the inletport my unloader valve s provded with a cut-awayportion or groove H' which is adapted to register with such inlet portand establish communication between it an the inlet chambeb.

For the operation of my loader valves, any suitable mechanism may beemployed, the same being ada ted to actuate said vah-'es either se aratey or in unson, in such manner as to e ect either a partial or completeremoval of the load due to compression. As heroin shown I provide forboth manual and automatic operation of the un loader valves so that thesame' may be under the control of the operator, or under the control ofthe pressure in a reservoir into which the comprossor discharges. Tothis end I provide a valve stern I which has its hearing m a bonnet orcap J Secured in suitable manner to the end of the valve chamber andoperatively connected with its unloader valve to transmit rota motionthereto. In the present instanee 's valve stem is provided with adiametrical projection or rib adapted to fit into the diauctrical slotin the outer end of its unloade' valve. T o the outer end of the valvestem is attached an Operating arm or level' K which is operatvelyconnected at one end with a corres onding arm K' by means of a link X.

or manual operation the last-mentioned arm K' is provided with a laveror handle Y, all as clearly shown in Fig. 4. It will be understood thatthe movement of this handle will cause rotary motion of both of theunloader valves in unison either from a normal or inoperative positionto an operative position or vice versa according to the direction ofmovement of the handle.

For the automatic operation of the unloader va'lves I provide agoverning or regulating mechaniem under the control of the air pressurein the reservoir (not shown) into which the com ressor discharges. Asshown in Figs. 4 an 5 one end of one of the arms or levers is pivotallyconnected to the piston rod L of a piston M which travels in a cylinderN. Ths pisten is normally held at one end of its chamber by means of aspital spring O which in turn holds the unloader valves in their nomnulor io mrative position. The piston M, however, s ndcr the controtof ugovel'or or regulating (leyce conprsing a casing or cylinder P havngcommunication wtl the cylinder N through the mlet pipe Q and exhaustpipe R respectively. The governor cylinder also has communication withthe reservoir through the supply pipe S entering such governor cylinderat the lower end the'cof and below the goi-'erning pisten T which isadapted to reeiprocat'e in the governor cylinder and to be movedupwardly by air pressure against the resistance of the coiled sprng Upressing downwardly against the upper end of such iston. This pistenalso acts as a valve for t e purpose of controlling the ports and p gand 1- whieh comnuncate with the nletand exhaust pipes Q and Rrespectively, said ports beng fol-med as annular chambers or grooves inthe inner walls of the governor cylinder.

\Vhenever the ressure delivered by the compressor into e reservoirreaches or exeeeds a maximum which he determined by the tension of thesprin U, itself regulated by the adjusting nut such pressure will forcethe pisten T upwardly, closing off the exhaust through the pipe R andadmtting the pressure through the inlet pipe with the result that theiston M wll forced outwardly against t e ressure of its spring O and thetwo unloa er valves will be simultaneousiy partially rotated so as tobring their cut-away portions H' into register `with the inlet ports d.The moving pa'ts of the conpressor, including the inlet valves, willoperate as before, but so long as the portion of the inlet port dgoverned by the unloader valve is thus kept open, the work of oompreionwill be interrupted, as the following explanaton will show.

It is evident that when the regular air compression action is inprogress, that portion of the inlet ort d governed by the valve D iscovered %y such latter valve during the movement of the piston B on itscompression stroke, and at such time the remaining portion of the inletport is cove-red by the unloader valve during such movement of thepisten, ths pru-*enting communication between the compression chamberand the inlet chamber b and allowing compression to take place as thepisten advances, and the compressed air to be discharged in the usualmanner past the disclarge Vals-'es F. However, when the unloader valvesere operated as just explained the relative movements of the piston andusual valve mechunisms will continue as usual but inasmuch as theunloader valves have been rotated to uncover portions of the inlet portsd, communication is tlereby Q, be

opened between the compressh'u chunheand the inlct 7), thusallowing theair in said compression chanber to pass freely to the nlet ohanlxir asthe piston advaooes. tlus 'reventing compression and causing theoonp'essor to operute without the lozni due to compression. When thepressure in the reservor is redured to the normal or pre- (leterninedamount the pistou T of the gov ernowill descend, therehy cutting ofl'further supply of air pressure through the pipe Q and releasing thepressure from the piston M through the exhaust pipe R. The spri O willthereupon return the parts, inclu ing the unloader valves, to theirnormal position, with the result that the ma chine will thereupon act tocompress and deliver air under pressu-e. By means of the lundle Y theunloader Valves may be operated by an operator or attendant at anydesired time, as for instanoe in starting the compressor when the loadshould be removed therefrom.

From the foregoing description it is evident that the unloder mechanismis comparatively simple, efiicient and conpact and morem-'er containsbut few parte and is 'easily constructed and applied. .Fm-thermore, myunloader is particularly adapted to act in connection with rotary orsemirotary air valves and is adapted to be arranged in the same vah-'eehamber.

I claim:

1. In conbination with an air compressor and its inlet port and inlet`valve therefor, an unloader Valve overning a portion of the inlet portand a apted to maintain such port open.

2. In comhination with an air coupressor and its inletport and inletvalve tlerefor, an nloadevalve governing a portion of the inlet portindependently of the inlet valve.

3. In combination with an air conpressor and its inlet port and inletvalve therefor, an unloadevalve overning a portion of the inlet port andaapted to maintain such port open, and a fluid pressure governor dericefor operatin the unloader valve.

4. In combinaton with an air compressor and its inlet port and inletvalve therefor, an unloade' Valve governing a portion of the inlet portand adapted to maintain such port open, and a flud pressure governoractuated by the excess pressure delivered by the compressofor Operatingthe unloader va ve.

In combinntion with an air compressor and its inlet port and inlet valvetlerefor, an uloader valve governing a portion of the inlet portindependently of the inlet valve, and means for Operating the unloadervalve nanually or automatically.

6. In combinatio with nn air cofnpressor and its inlet port und luletrlve therefo', i :n loa'lor vah-'e goveruig a portion of i the nletlport udependentiy of the inlet valve, sai( uloauler vuive being a'ru'igd in the same vlve ohamber as the inlet valve.

7. in unhiution with :n air eoup'essor and its ilet ports and inlet'mlves the'efor. unloader vulves governng portious of the inlet po'tsdependently of the inlet valves. and means for operuting the unlodervalvesl In conhination with an air conpressor and an inlet port and withan inlet valve, an uloadenvalve Operating independently of the inletvali-e, said vnlves having a coninon vali-'e ehamher and eontrollingportions of said inlet port, and means fo` operat-iu said uuloader Valveboth automatically an nanually.

9. In ronbiation with nn air conpressor including its compressioncylinder and its 'otary inlet valve, a rotary unloader vulve in axialalinenent with the inlet valve and independently governing communicationbetween the compression cylinde' and the inlet passage.

10. .In conhiation with an air copressor and an nlet port anti with aninlet valve Operating in a suitable valve chanber, an uloadevalvearranged in the same valve chanber inletvalve said vah-'es controllingportions of said inlet port.

11. In conbination with an air conpressor including its compressioncylinder and its 'otary inlet Valve, a rotary unloader vali-'e inaxiaialinenentwith the inlet vah-'e and independently goveringcommunication between the compression e i-'lindor and the inlet passage.said valves being arrungecl in the sn'e valve chanber and :hutting eachother at their :djacent eds.

12. In conhinztion with ill! air conp'essor including its compressioncylinder and its rotary inlet valre, a rotary unloader valve 'r'nged inaxial alinement with the inlet valve and in the same valve chanber, saidunloader vali-'e having a cut-away portion adapted to governcommunication between the compression cylinder and the inlet passageindependently of the inlet valve.

13. In conbinution with an air 'sonpressor and au iilet port and with aninlet valvc opomting in a suitable valre chanber, nn unloader valvearrangzed in the same valvuchanher and o ierating independently of theilet vali-'9. saik i vali-es governing po'tions of said iuiet port fluidpres-:sure uctuuted merhaisn for operatig the loader valve, and a fluidpressl'e govvrnor for udnitting fluid pressure to said nechanisn whenthe-pressure delivered by the (-onpressor oxceosls :1 prodeternineddegree.

14. I n comhinatio with an ir eonpressor and :n inlet port :ntl with :ninlet valve and Operating independently of the

